1. Field of Invention
This invention relates to an animal feed supplement and, in particular, to a solid animal feed supplement.
2. Brief Statement of the Prior Art
Molasses has been used for many years as an animal feed supplement together with additives such as phosphoric acid and feed nutrients such as urea, fats, and the like. Solid materials such as cottonseed meal have also been suspended in the molasses; however, difficulties have been experienced with maintaining a stable suspension of solid materials. The liquid supplements have been fed by application to fodder or by free choice feeding on lick-wheels.
Feed supplements have also been manufactured and marketed as solid blocks. The earliest blocks were pressed blocks which were formed by compressing mixtures of molasses and dry ingredients. Poured blocks, in which the ingredients are mixed with molasses and poured into containers where they solidify, are more recent developments. The earliest commercial poured block was prepared by evaporative heating of molasses similar to candy manufacturing as described in U.S. Pat. No. 3,961,081. All of the aforementioned blocks lack water resistance, and the evaporated molasses block also melted at elevated storage temperatures.
The most recent advance in supplement blocks is the poured chemical block, in which molasses is converted to water-resistance solids by additives. Large amounts of calcium oxide or magnesium oxide have been added to molasses and the resulting mixtures have been heated to form solids in the manner described in New Zealand Patent Specification No. 170,505. It has been found that solidification of molasses by this method is slow and requires substantial heating. The blocks which are formed are often too soft to limit their consumption and thus may require an additional appetite suppressant.
Entirely chemically gelled and hardened poured blocks and their manufacture are described in U.S. Pat. Nos. 4,027,043, 4,160,041 and 4,431,675. These blocks are prepared by the reaction of molasses, a soluble phosphate and the oxide or soluble salt of calcium and/or magnesium. No heating is required as the heat of reaction raises the temperature of the liquid mixture to between about 100.degree. F. and 160.degree. F. at the time it is poured into containers for solidification. Maximum hardness is attained by using both calcium and magnesium oxides.
Another method of manufacture of a poured block is shown in U.S. Pat. Nos. 4,171,385 and 4,171,386 in which the molasses is gelled with clay which is added with high shear agitation. Magnesium oxide is added to the liquid mixture and the hardness of the block can be increased by the addition of ferrous sulfate, as described in U.S. Pat. No. 4,265,916.
These products are intended for free choice or managed feeding. Unfortunately, in some free choice feeding situations, animals tend to overconsume the highly palatable molasses blocks, and appetite suppressants such as salt are often necessary ingredients. U.S. Pat. No. 4,431,675 discloses that the addition of magnesium oxide to a molasses block formed with calcium oxide and phosphoric acid increases its hardness sufficiently to limit its consumption without using appetite suppressants. The amount of magnesium oxide which must be used to achieve adequate hardness is usually much greater than the amount desired for nutrition, even though magnesium oxide is effective in prevention of grass tetany and acidosis and has been found to increase milk production of dairy cattle. In many applications none of these effects are needed, and in such applications the magnesium oxide is a costly ingredient without any nutritional benefit.